Roller Bearing Cage with Tangs

ABSTRACT

The invention relates to a roller bearing cage comprising: a first annular ring; a second annular ring; at least one retainer portion attaching the first annular ring to the second annular ring to form the first and second annular rings in a cylinder-type structure; and a plurality of resilient tangs on each of the first and second annular rings, each tang protruding from the circumference of the respective annular ring at an angle with respect to the plane of the respective annular ring and toward the other annular ring.

BACKGROUND TO THE INVENTION Field of the Invention

The present invention relates to rolling element bearing cages orrolling element bearing cage assemblies.

Description of the Related Art

Rolling element bearing cage assemblies are known in the art. A typicalassembly comprises an inner ring and an outer ring, and rolling elementsarranged in position between the inner ring and outer ring. The rollingelement bearing cage assembly maintains separation of the rollingelements and interconnects the rolling elements for uniform rotationwith respect to the inner and outer rings.

Example applications of a rolling element bearing cage assembly include,but are not limited to, automotive and truck transmissions, agriculturalconstruction equipment, pumps and compressors, and two-cycle enginessuch as marine outboards, and garden equipment.

An aim of the present invention is to provide an improved rollingelement bearing cage assembly.

SUMMARY OF THE INVENTION

There is provided a rolling element bearing cage assembly design havingan increased load carrying ability, and more economic production coststhan known rolling element bearing cage assemblies.

There is provided, in a first aspect, a novel structure. The novelstructure provides a rolling element bearing cage assembly with tangswhich are resilient.

In a first aspect there is provided a rolling element bearing cagecomprising: a first annular ring; a second annular ring; at least oneretainer portion attaching the first annular ring to the second annularring to form the first and second annular rings in a cylinder-typestructure; and a plurality of resilient tangs on each of the first andsecond annular rings, each tang protruding from the circumference of therespective annular ring at an angle with respect to the plane of therespective annular ring and toward the other annular ring.

Each annular ring may have an inner circumference and an outercircumference, wherein the at least one retainer portion is connected tothe inner circumferences of the annular rings and the plurality ofresilient tangs are connected to the outer circumferences.

Each resilient tang may have a first tang edge connected to therespective annular ring and a second tang edge opposite the first tangedge, wherein the length of the second tang edge is greater than thelength of the first tang edge. Ends of the second tang edge may defineretaining elements. The edges of the tangs between the first and secondtang edges may define retaining elements. The retaining elements may befor retaining rolling elements. The distance between the ends ofadjacent second tang edges may accommodate rolling elements. The thirdand fourth tang edges may join the first tang edge to the second tangedge are shaped to accommodate a rolling element. The shape of the thirdand fourth tang edges may be determined by the angle of the tangs to theplane of the annular rings.

Each annular ring may have a circumferential width defining a first andsecond edge, wherein the distance between the first edges of the annularrings corresponds to the space required to accommodate a rolling elementat that edge.

There may be provided a plurality of retainer portions, and the spacingbetween adjacent retainer portions is less than the radius of a rollingelement to be accommodated in the rolling element bearing cage.

The number of tangs may correspond to a number of rolling elements.

At least one retainer portion may be joined to the annular rings at acircumferential position on each annular ring which corresponds to thecircumferential position of the first tang ends of an opposing pair ofresilient tangs.

The circumferential position of connection of the at least one retainerportion to the inner circumference of the annular rings may be alignedwith the circumferential position of connection of the opposing pair ofresilient tangs to the outer circumference of the annular rings.

There may be provided a plurality of retainer portions attaching thefirst annular ring to the second annular ring. Each retainer portion maybe joined to the annular rings at circumferential positions on eachannular ring which correspond to the circumferential position of thetang ends of each of opposing pairs of resilient tangs. Thecircumferential position of connection of the retainer portions to theinner circumference of the annular rings may be aligned with thecircumferential position of connection of the opposing pairs ofresilient tangs to the outer circumference of the annular rings.

The retainer portions may be, of a thickness such that they form atleast part of the tangs.

The first annular ring and the second annular ring may each comprise onepart.

The first annular ring and the second annular ring may each comprisestwo parts.

The first annular ring and the second annular ring may each comprisethree or more parts.

In a second aspect there is provided a method of forming a rollingelement bearing cage comprising: forming a planar strip of material,having a length corresponding to a circumferential dimension of arolling element bearing cage; forming openings in the planar strip,corresponding to positions at which rolling elements are to be located;forming a plurality of tangs, alongside and part of each side of thelength of the planar strip, each tang having a first tang edge of afirst length adjoining the strip and a second edge of a second lengthopposite the first tang edge; and bending each side of the length of thestrip such that the plurality of tangs is positioned at an angle withrespect to the planar strip, wherein the fold is through an angle ofgreater than 90° and less than or equal to 180° relative to the plane ofthe planar strip.

The method may further comprise an initial bending step comprisingbending the planar strip of material such that the planar strip ofmaterial forms at least part of the circumference of a cylindrical-typestructure with the tangs protruding therefrom, the following bendingstep then bending the bent part of the planar strip.

The method may further comprise bending the planar material such thatmaterial forms a part of the circumferential section of a cylinder-typestructure.

In a third aspect there is provided a rolling element bearing cageformed of one or more segments, each segment comprising: a supportingframe having a plurality of spaced apart openings each for accommodatinga rolling element; and a reinforcing frame, inserted within thesupporting frame, having a corresponding plurality of openings each foraligning with the openings of the supporting frame.

The supporting frame and the reinforcing frame may be made of differentmaterials.

The material of one of the reinforcing frame and the supporting framemay be more durable than the material of the other.

The material of one of the reinforcing frame and the supporting framemay be more expensive than the other.

The reinforcing frame may be provided with a plurality of internalvoids, the voids being filled with a filling material.

The supporting frame and the reinforcing frame may be indistinct fromeach other, and the resulting frame is provided with a plurality ofinternal voids, the voids being filled with a filling material.

The filling material may be the same material as the material of one ofthe supporting frame or the reinforcing frame.

The supporting frame may be provided with an internal void, thereinforcing frame being retained by being positioned within said void.

The supporting frame may comprise: a first annular ring; a secondannular ring; a plurality of retainer portions attaching the firstannular ring to the second annular ring to form the first and secondannular rings in a cylinder-type structure; and a plurality of tangs oneach of the first and second annular rings, each tang protruding fromthe respective annular ring at an angle with respect to the plane of therespective annular ring and toward the other annular ring.

The retainer portions may attach opposing tangs of the first and secondangular rings.

The reinforcing frame may be provided through the internal void of thesupporting frame.

The reinforcing frame may comprise a third annular ring. The thirdannular ring may be shaped to have edges which are accommodated byinternal grooves in the first and second annular rings, and a centralportion which is shaped to have openings between the retainer portions.

One or more openings of the reinforcing frame may protrude from thesupporting frame, one or more openings of the supporting frame are notaligned with an opening of the reinforcing frame, and each other openingof the supporting frame is aligned with an opening of the reinforcingframe. The protruding portion of the reinforcing frame of a firstsegment may engage with the supporting frame of a second segment suchthat the one or more openings of that reinforcing frame align with theone or more openings in that supporting frame not aligned with the oneor more openings of the reinforcing frame of that segment.

A rolling element may be provided in the at least one opening.

The protruding portion of the reinforcing frame of another segment mayengage with the supporting frame of the first segment such that the oneor more openings of that other reinforcing frame align with the one ormore openings of that supporting frame.

The supporting frame may have a plurality of retainer portions betweeneach opening, the reinforcing frame being positioned within thesupporting frame such that it is rotated within the supporting frame byat least one complete retainer portion, one opening, and part of onefurther retainer portion, thereby a section of the reinforcing frameprotruding from the supporting frame and a section of the supportingframe having a recessed section where the reinforcing frame is rotatedfrom.

The section of the reinforcing frame protruding from the supportingframe of a first segment may engage with a recessed section of asupporting frame section of a second segment.

The rolling element bearing cage may be provided with one or morerolling elements provided in the one or more openings.

The section of the supporting frame having a recessed section of thefirst segment may engage with a protruding part of another segment.

One or more rolling elements may be provided in the one or more openingsassociated with the recessed section of the first segment and theprotruding part of the other segment.

The rolling element may be any one of: a cylindrical roller; a taperroller; a spherical roller; a ball.

In a fourth aspect there is provided a rolling element bearing cageformed of one or more segments, each segment comprising: a supportingframe having a plurality of spaced apart openings each for accommodatinga rolling element; and a reinforcing frame, inserted within thesupporting frame, having a corresponding plurality of openings each foraligning with the openings of the supporting frame, wherein thesupporting frame and the reinforcing frame are made of differentmaterials.

In a fifth aspect there is provided a rolling element bearing cageformed of one or more segments, each segment comprising: a supportingframe having a plurality of spaced apart openings each for accommodatinga rolling element; and a reinforcing frame, inserted within thesupporting frame, having a corresponding plurality of openings each foraligning with the openings of the supporting frame, wherein at least oneopening of the reinforcing frame protrudes from the supporting frame, atleast one opening of the supporting frame is not aligned with the one ormore openings of the reinforcing frame, and each other opening of thesupporting frame is aligned with the one or more openings of thereinforcing frame.

In a sixth aspect there is provided a rolling element bearing cageformed of one or more segments, each segment comprising: a supportingframe having a plurality of spaced apart openings each for accommodatinga rolling element; and a reinforcing frame, inserted within thesupporting frame, having a corresponding plurality of openings each foraligning with the openings of the supporting frame, wherein thesupporting frame has a plurality of retainer portions between eachopening, the reinforcing frame being positioned within the supportingframe such that it is rotated within the supporting frame by at leastone complete retainer portion, one opening, and part of one furtherretainer portion, thereby a section of the reinforcing frame protrudingfrom the supporting frame and a section of the supporting frame having arecessed section where the reinforcing frame is rotated from.

In a seventh aspect there is provided a method of forming a rollingelement bearing cage assembly, comprising forming one or more segments,the forming of each segment comprising: forming a supporting framehaving a plurality of spaced apart openings; forming a reinforcing frameincluding a corresponding plurality of openings each for aligning withthe openings of the supporting frame; and inserting the reinforcingframe within the supporting frame.

The method may comprise forming the supporting frame of a first materialand forming the reinforcing frame of a second material, the secondmaterial being different to the first material.

The method may comprise providing the reinforcing frame with a pluralityof internal voids, the voids being filled with a filling material.

The supporting frame and the reinforcing frame may be indistinct fromeach other, and the resulting frame is provided with a plurality ofinternal voids, the voids being filled with a filling material.

The method may comprise forming at least one void in the supportingframe, wherein the reinforcing frame is retained by being positionedwithin said at least one void.

Forming the supporting frame may comprise: forming a part of acylinder-type structure comprising part of a first annular ring and partof a second annular ring held connected by a plurality of retainerportions.

Forming the reinforcing frame may comprise: forming a part of a furthercylinder-type structure comprising part of a further first annular ringand part of a further second annular ring held connected by a pluralityof further retainer portions.

The step of inserting may comprise providing the reinforcing framethrough voids in the supporting frame.

A void may be formed in each retainer portion.

Forming the supporting frame may comprise: forming a part of acylinder-type structure comprising part of a first annular ring and partof a second annular ring held connected by a plurality of retainerportions, and wherein the step of inserting comprises providing thereinforcing frame through voids in the supporting frame.

The cylinder type structure may comprise a plurality of tangs formedalong the outer circumference of each of the first and second annularrings, at an angle to the plane of the respective annular ring andtoward the other annular ring.

At least part of the cylinder-type structure is formed using 3Dmoulding, 3D printing or 3D additive manufacturing.

At least part of the cylinder-type structure may be at least part of therolling element bearing cage, and one or more parts are connected toform a rolling element bearing cage.

This can be one segment with a joint to allow insertion that is thenjoined to itself to form the cage.

The step of inserting may be such that at least one opening of thereinforcing frame protrudes from the supporting frame, at least oneopening of the supporting frame is not aligned with the one or moreopenings of the reinforcing frame, and each other opening of thesupporting frame is aligned with an opening of the reinforcing frame,the method further comprising: connecting the one or more segments, theconnecting comprising: engaging the protruding portion of thereinforcing frame of a first segment with the recessed portion of thesupporting frame of a second segment such that the one or more openingsof that protruding portion of the reinforcing frame aligns with the oneor more openings in that supporting frame not aligned with the one ormore openings of the reinforcing frame of that segment. In the case ofonly one segment, the connection is inserting the protruding portion ofthe segment into the recessed portion of the same segment.

The step of connecting may further comprise: engaging the protrudingportion of the reinforcing frame of the second segment with thesupporting frame of the first segment such that the one or more openingsof that reinforcing frame aligns with thee one or openings in thatsupporting frame not aligned with an opening of the reinforcing frame ofthat segment. For only one segment this connection is to itself.

The method may further comprise the step, after the connecting, of:inserting a rolling element in each opening.

The rolling element bearing cage assembly may comprise one or moresegments, each segment formed and connected according to above methods,the segments forming, when all connected, a cylindrical-type structure.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described with reference to the accompanying drawings,in which:

FIG. 1 illustrates an exemplary rolling element bearing cage assembly;

FIG. 2 illustrates an exemplary resilient tang of the rolling elementbearing cage assembly of FIG. 1;

FIG. 3 illustrates a view of the exemplary rolling element bearing cageassembly of FIG. 1, without tangs;

FIG. 4 illustrates the exemplary view of FIG. 3 with the tangs included;

FIG. 5 illustrates a view through a cross-section of FIG. 4;

FIG. 6 illustrates the exemplary rolling element bearing cage assemblyof FIG. 1 with rolling elements;

FIGS. 7A, 7B and 7C illustrate views of the exemplary rolling elementbearing cage assembly of FIG. 6, with tangs included;

FIG. 8 illustrates a view through a cross-section of FIG. 7A;

FIGS. 9A and 9B illustrate an exemplary tang;

FIG. 10 is a view of an exemplary half rolling element bearing cageassembly;

FIG. 11 is a view of an exemplary connector for connecting two halfrolling element bearing cage assemblies;

FIG. 12 illustrates an exemplary rolling element bearing cage assemblycomprising two halves of a rolling element bearing cage assemblyconnected together;

FIG. 13 illustrates an exemplary planar strip informing the rollingelement bearing cage assembly with tangs during fabrication;

FIG. 14 illustrates a cross-sectional view of the rolling elementbearing cage assembly of FIG. 13 during fabrication;

FIG. 15 illustrates an alternate view of the rolling element bearingcage assembly of FIGS. 13 and 14 after the material has been formed;

FIG. 16 illustrates a view of an exemplary rolling element bearing cageassembly without tangs and with an additional supporting materialcorresponding to the arrangement of FIG. 3 but with additionalsupporting material;

FIGS. 17A and 17B illustrates alternate views through a cross-section ofFIG. 16 in two different arrangements;

FIG. 18 illustrates a rolling element bearing cage assembly according toFIGS. 16 and 17;

FIG. 19 illustrates an exemplary rolling element bearing cage assemblyconsistent with FIGS. 16 to 18;

FIG. 20 illustrates an exemplary rolling element bearing cage assemblyconsistent with FIGS. 16 to 19;

FIGS. 21A, 21B, and 21C illustrate an exemplary rolling element bearingcage assembly having an outer cage and an inner insert;

FIG. 22 illustrates half of a rolling element bearing cage assemblymanufactured by 3D moulding, 3D printing, additive manufacturing; and

FIG. 23 illustrates a rolling element bearing cage assembly manufacturedby 3D moulding, 3D printing, additive manufacturing.

DESCRIPTION OF PREFERRED EMBODIMENTS

The invention is now described with reference to examples andembodiments.

FIG. 1 illustrates an exemplary rolling element bearing cage assemblygenerally designated by reference numeral 2.

The rolling element bearing cage assembly 2 comprises a first annularring 4 a and a second annular ring 4 b. The first and second annularrings are connected together to form a cylindrical-type structure. Thefirst annular ring 4 a forms one end of the cylindrical-type structure,and the second annular ring 4 b forms the other end of thecylindrical-type structure.

Each annular ring 4 a, 4 b preferably has an inner circumference and anouter circumference. With reference to FIG. 1, the annular ring 4 a hasan inner circumference 3 a and an outer circumference 3 b. The annularring 4 b has an inner circumference 5 a and an outer circumference 5 b.The inner and outer circumferences are formed by concentric rings of therespective annular ring, with the outer circumference being defined by alarger radius (or diameter) than the inner circumference.

A plurality of retainer portions 10 join the first annular ring 4 a tothe second annular ring 4 b. Each retainer portion 10 has one endconnected to the first annular ring 4 a at spaced locations around itsinner circumference 3 a, and the other end connected to the secondannular ring 4 b at spaced locations around its inner circumference 5 a.The plurality of retainer portions 10 are of the same dimensions. Eachretainer portion 10 has the same length, and extends by this length fromthe first annular ring inner circumference 3 a to the second annularring inner circumference 5 a, such that the planes of the first andsecond annular rings 4 a, 4 b are substantially parallel with eachother.

The retainer portions 10 and the first and second annular rings 4 a, 4 bform a cylindrical-type structure.

The rolling element bearing cage assembly 2 cylindrical-type structurehas cylindrical sidewalls formed of the plurality of retainer portions10. In the sidewalls of the cylindrical-type structure there areprovided the plurality of retainer portions 10 each extending from thefirst annular ring inner circumference to the second annular ring innercircumference 5 a. Interspersed with the retainer portions 10 is aplurality of spacer segments 12 which have first and second edgesdefined by the edges of successive retainer portions 10, and third andfourth edges defined by the inner circumferences 3 a, 5 a of the firstand second annular rings 4 a, 4 b.

The sidewalls of the cylinder-type structure are thus formed by theretainer portions 10 interspersed alternately with spacer segments 12.The spacer segments 12 are gaps between the retainer portions 10.

Each annular ring 4 a, 4 b is provided with a plurality of resilienttangs 8 attached to its respective outer circumference 3 b, 5 b. Thefirst annular ring 4 a and the second annular ring 4 b are each providedwith a plurality of resilient tangs 8 corresponding to the plurality ofretainer portions 10. Each resilient tang 8 is located on the first orsecond annular ring outer circumferences 3 b, 5 b generally proximate tothe connection point of the retainer portion 10. Each resilient tang 8on the outer circumference 3 b of the first annular ring 4 a is pairedwith each tang on the outer circumference 5 b of the second annular ring4 b. Resilient tangs 8 positioned at opposite ends of the retainerportion 10 are paired. The number of paired resilient tangs 8 thuscorresponds to the number of retainer portions 10.

In the cylindrical-type structure the resilient tangs 8 on each annularring 4 a, 4 b are disposed in a direction away from the plane of theannular ring and toward the sidewall of the cylindrical-type structure.This is explained in further detail later.

The spacer segments 12 are for accommodating rolling elements, asdiscussed further hereinbelow. The dimensions of each spacer segment 12is configured to accommodate a rolling element.

In the illustration of FIG. 1 the retainer portions are attached at theinner circumference of the annular rings and the tangs are attached atthe outer circumference of the annular rings. In alternativearrangements this may be reversed with the retainer portions attached atthe outer circumference of the annular rings and the tangs attached atthe inner circumference of the annular rings.

In alternatives, a single element may provide a retainer portion and apair of opposing tangs. For example, a retainer portion may join theannular rings, and the tangs protrude from the retainer portion.

With reference to FIG. 2 there is shown in further detail the structureof an exemplary resilient tang 8. Each resilient tang 8 has a first tangedge 20, a second tang edge 22, a third tang edge 24, and a fourth tangedge 26.

The first tang edge 20 may be connected to a respective outercircumference 3 b, 5 b of the first or second annular rings 4 a, 4 b.The second tang edge 22 is substantially parallel to the first tang edge20, although the disposition of the resilient tangs on the respectiveannular rings may, in situ, distort this parallel relationship. Thisdistortion may be as a result of the curved nature of the annular rings.The first tang edge 20 has a shorter length than the second tang edge22.

The third and fourth tang edges 24 and 26 are of the same length, andconnect the ends of the first tang edge 20 to the ends of the secondtang edge 22.

The ends of the second tang edge 22 are identified by reference numerals22 a and 22 b and are referred to as second tang edge ends.

The purpose of the tangs is to assist in securely positioning a rollingelement in a spacer segment, as will be discussed further below. Thefirst tang edge 20 is connected to the first or second annular ringouter circumference, and the second tang edge ends 22 a, 22 b engage arolling element positioned in a spacer segment. Alternatively or inaddition, the third 24 and fourth 26 tang edges may engage a rollingelement positioned in a spacer segment.

FIG. 3 illustrates the structure of the sidewalls of the cylinder-typerolling element bearing cage assembly in more detail, but for ease ofillustration without the tangs. FIG. 3 illustrates the sidewall as aflat, elongated element for ease of reference. In practice this elementis curved or bent in order to provide the sidewall structure as shown inFIG. 1.

Shown in FIG. 3 is: a portion of the first annular ring 4 a; a portionof the second annular ring 4 b; two retainer portions 10 a, 10 b whichconnect the first and second annular ring inner circumferences 3 a, 5 a,and form part of the sidewall of the cylindrical-type structure; aspacer segment 12 b; and portions of two further spacer segments 12 a,12 c.

The spacer segment 12 b is provided between the two retainer portions 10a and 10 b. In general the sidewall of the cylindrical-type structurecomprises a plurality of retainer portions interspersed with a pluralityof spacer segments 12.

The spacer segment 12 b has a first pair of opposing walls 42 a, 42 bdefined by the edges of the adjacent retainer portions 10 a, 10 b, and asecond pair of opposing walls 40 a, 40 b defined by the segments of thefirst 4 a and second 4 b annular ring inner circumferences respectively.In general the spacer segments 12 define an area of space between theretainers 10 and between the first 4 a and second 4 b annular rings toaccommodate rolling elements as discussed below.

FIG. 4 illustrates the structure of the cylinder sidewalls of therolling element bearing cage assembly as shown in FIG. 3, but furtherexpanded to include the resilient tangs 8.

As shown in FIG. 4, resilient tang pairs are labelled by referencenumerals 8 a, 8 b. The resilient tangs are disposed to point inwardly ofthe cylindrical-type structure. This inward disposition means that thetangs extend toward a direction along the sidewalls, but external to theinternal cylindrical-type structure.

In FIG. 4 the second tang edge ends 22 a, 22 b are denoted.

The formation of the resilient tangs 8 is further illustrated by FIG. 5,which shows a cross-section through FIG. 4 along the dashed line denotedby A-A.

As shown in FIG. 5, the resilient tangs 8 a, 8 h extend from therespective annular rings 4 a and 4 b. The annular rings are joined bythe retainer 10 b. The resilient tangs 8 are connected to the annularrings 4 a, 4 b at a position proximate to where the retainer portions 10are connected to the annular rings 4 a, 4 b. The resilient tangs areconnected to the annular rings outer circumference 3 b, 5 b, along thefirst resilient tang edge 20.

The retainer portions 10 are for positioning and retaining rollingelements within the space segments 12, and the second tang edge ends 22a, 22 b are utilised for retaining rolling elements in the spacesegments. As noted above, the third 24 and fourth 26 tang edges mayalternatively or additionally be used for retaining the rollingelements.

The dimensions of the space segments 12 between the first and secondannular rings is determined in order to accommodate required rollingelements. The second tang edge ends 22 a, 22 b of the resilient tangs 8are also provided to retain required rolling elements within the spacesegments, and the tangs 8 are thus appropriately shaped and dimensionedto permit this. When used to retain the rolling elements, the third 24and fourth 26 tang edges may be appropriately shaped.

With reference to FIG. 6, there is shown the exemplary rolling elementbearing cage assembly of FIG. 1 with rolling elements positionedtherein. A plurality of rolling elements are provided, generallydesignated by reference numeral 30, with each rolling element beinglocated within a space segment 12.

FIG. 7A illustrates the structure of the cylinder sidewalls of therolling element bearing cage assembly as shown in FIG. 4, but furtherexpanded to include the rolling elements 30. Each rolling element 30occupies a space segment 12. As with FIG. 4, this illustrates a viewfrom above. FIG. 7B illustrates a side view of FIG. 7A. With referenceto FIGS. 7A and 7B, like reference numerals are used for elements whichcorrespond to FIG. 4.

A rolling element 30 b is located within the space segment 12 b. Alsoshown are portions of a rolling element 30 a located in space segment 12a, and rolling element 30 c located within space segment 12 c. Therolling element 30 b as illustrated in FIG. 7A has first and secondedges 31 a, 31 b alongside first and second edges 42 a, 42 b of thespacer segment. The rolling element 30 b as illustrated in FIG. 7A alsohas third and fourth edges 31 c, 31 d alongside the first and secondedges 42 c, 42 d of the space segment.

As shown in the sideview of FIG. 7B, the rolling element 30 b ispositioned such that the annular rings do not intersect the centralpoint 35 of the rolling element 32 b.

The location of rolling element 30 b in a space segment 12 b leavesspaces along the edges of the rolling element within the space segment12 b. Similarly for all rolling elements there is such space along theedges within the space segment they are positioned. This space allowsthe rolling elements 30 to rotate as necessary. The rolling elements arenot fixably positioned in the space segments. The drawings are not toscale, and the spaces shown do not represent actual dimensions. Arolling element may in fact move about the edges of the space segment 12within which it is positioned.

In FIGS. 7A and 7B the second tang edge ends 22 a, 22 b are denoted. Thesecond tang edge ends 22 a, 22 b each abut a rolling element surface inthe space segment 12 adjacent a retainer portion 10.

A rolling element such as rolling element 30 b may be held in the spacesegment 12 b by the resilient tangs 8. The second tang edge ends 22 a,22 b prevent the rolling element 32 b moving upwards (with reference tothe illustration of FIG. 7B, and the space segment dimensions preventthe rolling element 32 b moving downwards. The distance between adjacentretainer portions is less than the rolling element diameter. The rollingelement 32 b is thus held in position.

For completeness FIG. 7C illustrates a view of the arrangement of FIG.7A from below.

The formation of the resilient tangs 8 is further illustrated by FIG. 8,which shows a cross-section through FIG. 7A along the dashed linedenoted by B-B. FIG. 8 corresponds to FIG. 5, but with a rolling elementin situ.

As shown in FIG. 8, the resilient tangs 8 a, 8 b extend from therespective annular rings 4 a and 4 b. The annular rings innercircumferences are joined by the retainer portion 10 b. The resilienttangs 8 are connected to the annular rings outer circumferences at aposition proximate to where the retainer portions are connected to theannular ring inner circumferences. The resilient tangs are connected tothe annular rings along the first tang edge 20. The rolling element 30 bis shown in FIG. 8.

As noted above with reference to FIG. 5, the dimension of the spacesegments 12 between the first and second annular rings is determined inorder to accommodate required rolling elements. The dimensions of theretainer portions 10 between adjacent retainer portions is alsodetermined in order to accommodate required rolling elements. The secondtang edge ends 22 a, 22 b of the tangs 8 are also provided to retainrequired rolling elements within the space segment, and the tangs arethus appropriately shaped and dimensioned to permit this. The shapingand dimensioning of the tangs in order to achieve this comprisesdetermining the length of the second tang edge 22, and determining theangle at which the tang should be disposed to extend from the annularring.

With reference to FIGS. 9A and 9B, there is illustrated tworepresentations of the tang in respect of which dimensions and anglesassociated with the tang for retaining a rolling element in place can beunderstood.

FIG. 9A provides a view which corresponds to FIG. 5, showing a pair oftangs 8 a, 8 b, the annular rings 4 a, 4 b, and the retainer portion 10b.

FIG. 9B shows a view corresponding to FIG. 2, but showing the tang 8positioned in connection to the annular ring 4 a.

As shown in FIG. 9A, the tang 8 extends from the annular ring 4 a by alength dimension w, and extends at an angle α relative to the retainerportion 10 b. The dimension w extends from the outer circumference ofthe annular rings to the second tang edge.

As shown in FIG. 9B, the first edge of the tang has a dimension y, thesecond edge of the tang has a dimension x, the first and second edges ofthe tang are separated by a radial distance z. The dimension z is thevertical height of the tang over the outer circumference of the annularring. It is not the physical length of the third and fourth tang edges.

The second edge of the tang is longer than the first edge of the tang(x>y) such that the third tang edge (viewed radially) which extends fromthe first tang edge and to the second tang edge end, extends by an angleβ.

With reference to FIG. 10, there is illustrated half of the exemplaryrolling element bearing cage assembly of FIG. 1, which is generallydesignated by reference numeral 36. Consistent with FIG. 1, there isshown a first half of the first annular ring 4 a denoted by referencenumeral 4 a 1, a first half of a second annular ring 4 b denoted byreference numeral ring 4 b 1. A plurality of retainer portions 10 areshown, and a plurality of space segments 12 are shown. A plurality oftangs 8 are also shown.

In the half rolling element bearing cage assembly 36 of FIG. 10, thereis shown two ends denoted by reference numerals 38 a and 38 b. Each endcomprises the rolling element bearing cage being terminated at a halfretainer portion, which reference numerals 38 a and 38 b denote. Thehalf rolling element bearing cage assembly shown in FIG. 10 may bematched with another half rolling element bearing cage assembly, and onconnecting together each half terminates with half of a retainer portion38 a, 38 b which can be joined together to form a whole retainerportion.

As also shown in FIG. 10, the half of the retainer portion 38 acomprises two slots 40 a and 42 a, and the half of the retainer portion38 b comprises two slots 40 b and 42 b. These slots on each half of theretainer portion can engage with a connector, to allow two halves of arolling element bearing cage to be joined together.

FIG. 11 illustrates an exemplary connector for joining two rollingelement bearing cage assembly halves as illustrated in FIG. 10. Aconnector generally designated by reference numeral 48 has fourengagement protrusions 50 a, 50 b, 52 a, 52 b on a surface 56 thereof.Two connectors 48 are required to connect two rolling element bearingcage assembly halves.

The surface 56 is provided to interface with a surface of the retainerportion. The protrusions 50 a and 52 a are provided to engage with theslots 40 a and 42 a, and the protrusions 50 b and 52 b are arranged toengage with the slots 40 b and 42 b respectively. In this way aconnector 48 can be used at each location 38 a, 38 b to connect the tworolling element bearing cage assembly halves together.

The connector 48 is shaped in order to fit into the space availableabove the retainer portions comprised of the two half retainer portions38 a, 38 b. The connector 48 therefore preferably has a profile to allowit to be accommodated within the space available between the retainerportions and the associated two half tang pairs.

FIG. 12 illustrates an arrangement in which two rolling element bearingcage assembly halves such as shown in FIG. 10 have been joined together.For ease of illustration the joining together before the fixing of theconnector 48 is illustrated.

As shown, the half retainer portion 38 a is joined to another halfretainer portion 38 b of another rolling element bearing cage assemblyhalf. Similarly the other half retainer portion 38 b is joined toanother half retainer portion 38 a.

FIGS. 10 to 12 illustrate how two rolling element bearing cage assemblyhalves, once formed, may be connected together to form a whole rollingelement bearing cage assembly.

It should be noted that this description sets forth an example where therolling element bearing cage assembly is made of two halves, where therolling element bearing cage is formed of multiple segments, it may beformed of two or more segments, and the segments are not limited tobeing halves.

With reference to FIGS. 13 to 15, there is illustrated an example of howeach half of the rolling element bearing cage assembly may be formed.

FIG. 13 illustrates a sheet of material, such as a metal material, whichmay be formed to have the shown shape with the tang shapes protrudingfrom the edge thereof. Also shown are the space segments 12 which may bestamped or machined-out from the material.

Shown in FIG. 13 are dashed lines labelled C, D, E, and F. FIG. 14 showsthe material of FIG. 13 from a different angle, which shows the planarstructure of the material. Also shown are the dashed line C, D, E, and Fin relation to this view.

The structure as shown in FIG. 13 is first rolled into a half cylindershape, and then formed along the then curved lines C, D, E and F to formthe sectional shape as shown in FIG. 15—to arrive at the curved rollingelement bearing cage half structure as shown in FIG. 10. The pointsassociated with dashed lines C, D, E and F are shown in FIG. 15.

The structure as shown in FIG. 15 is then bent, to arrive at the curvedstructure such as shown in FIG. 1.

Whilst the lines C and D, E and F are shown as aligned in FIG. 15, theillustration is merely to show where the retainer portions end, theannular rings start, and where the tangs begin.

With reference to FIG. 16, there is shown a further arrangement in whicha second material is used for the formation of part of the rollingelement bearing cage assembly.

FIG. 16 illustrates a rolling element bearing cage assembly similar toFIG. 3, but an additional piece of material 60 is provided. As with FIG.3, the resilient tangs 8 are omitted for ease of illustration.

The additional material may be provided on top of the retainer portionsegments of the rolling element bearing cage structure or sandwichedwithin the retainer portion segments. The material is provided as asingle layer of material 60.

In an example of FIG. 16, this material 60 is provided on top of theretainer portion segments. FIG. 17A shows a cut-through section G-G ofFIG. 16, although in FIG. 17A the tangs 8, not shown in FIG. 16 for easeof illustration, are also shown. FIG. 17A thus corresponds to FIG. 5.

The additional material 60 is shown in FIG. 17A, which it can be seen isformed within the rolling element bearing cage structure previouslydefined. The rolling element bearing cage assembly can thus be formedwith the two component parts being formed together.

FIG. 17B illustrates the alternative arrangement in which the material60 is sandwiched within the retainer portion 10.

In general the rolling element bearing cage assembly may be enhanced orstrengthened by the provision of the additional material, and theformation of the additional material will depend on the formation of therolling element bearing cage assembly.

FIG. 18 shows a half of an exemplary rolling element bearing cageassembly, a similar view to that of FIG. 10, with the material 60included. The rolling element bearing cage assembly of FIG. 18 includesthe additional material, and also shows that opposing resilient tangsare joined together by an integrated further retainer portion. The areabetween each retainer portion and an associated joined pair of opposingtangs may be largely or completely filled. This may simplify themanufacturing process, and/or may enhance the robustness of the rollingelement bearing cage assembly.

As such, whether the additional material is placed on top of theretainer portions or sandwiched within the retainer portions is notimportant, as the additional material may become sandwiched merely byfilling the area.

The material 60 may be formed and shaped separately to the forming andshaping of the cylindrical rolling element bearing cage structure, andthen integrated with the half rolling element bearing cage structure.FIG. 19 shows a cylindrical half rolling element bearing cage structureand a corresponding material 60, suitably shaped for inserting. FIG. 20shows the material 60 being inserted to the rolling element bearing cagestructure.

The material 60 may be a different material to that with which theremainder of the rolling element bearing cage structure is formed. Thematerial 60 may provide a wear strip, which has different propertiesthan the remainder of the material of the rolling element bearing cagestructure. The main rolling element bearing cage structure may be formedof one material of a first cost, and then the material 60 of a secondcost added. The second cost may be higher than the first cost, but theoverall cost of the rolling element bearing cage assembly is reducedcompared to what would have been required to manufacture the wholerolling element bearing cage assembly with the second material.

An example of the material 60 is brass, bronze or ToughMet®, but othermaterials could also be used.

Overall the use of the additional material 60 allows an integratedrolling element bearing cage structure to be formed which has betterproperties than the homogenous rolling element bearing cage structurepreviously defined.

With this technique the material 60 can be provided of a different typeof material to the remainder of the rolling element bearing cagestructure.

The arrangement of FIG. 18 illustrates a different arrangement forconnecting cylindrical rolling element bearing cage halves: thearrangement will be different in different implementations, and ingeneral some mechanism for each half of the rolling element bearing cageto engage is required. Of course, as noted above, there may be more thantwo segments, but the arrangement is described with reference to twohalves.

An alternative implementation for assembling a rolling element bearingcage assembly and including an additional material therein isillustrated with respect to FIGS. 21A, 21B, and 21C. Again this isdescribed with reference to two halves, but in general applies tomultiple segments.

FIG. 21A shows part of a rolling element bearing cage assembly 36,including the annular rings 4 a and 4 b joined by retainer portions 10,and having spacer segments 12. In the example as shown in FIG. 21A,opposing resilient tangs are joined. Thus the tangs 8 a and 8 b arejoined by a portion 66 as shown.

An additional material is formed having the same general shape as theportion of the rolling element bearing cage assembly part 36, which canbe slotted into the structure comprising the annular rings 4 a, 4 b.Thus there is shown a portion 62 which has retainer portions and spacersegments which are consistent with the retainer portions and spacersegments of the rolling element bearing cage assembly 36 when slottedthrough.

Thus, in general, a rolling element bearing cage is formed of one ormore segments. Each segment comprises a, supporting frame 36 having aplurality of spaced apart openings each for accommodating a rollingelement. Each segment also comprises a reinforcing frame 62, insertedwithin the supporting frame, and having a corresponding plurality ofopenings each for aligning with the openings of the supporting frame.

The supporting frame has an internal void through which the reinforcingframe is formed.

Preferably each end of the portions 62 is provided with an engagementmechanism, which engages with another insert to another half of arolling element bearing cage assembly.

As shown in FIG. 21A, each portion of the insert 62 which sits between aretainer portion and its associated resilient tang pairs has a slot orcavity 64 therein.

The insert 62 may be formed of an additional material as discussedhereinabove.

The supporting frame 36 and the reinforcing frame 62 may be formed ofthe same or different materials. If different, one material may be moreexcessive than the other, and/or one material may be more robust ordurable than the other.

FIG. 21B shows the half rolling element bearing cage assembly 36 pairedwith another half rolling element bearing cage assembly, with the insert62 fully inserted within each half. Each insert 62 is provided with anengagement mechanism at its end, which engages with the insert of theother half of the rolling element bearing cage assembly. Thus the twohalves of the rolling element bearing cage assembly are secured togetherby the engagement between the two inserts 62.

As shown in FIG. 21A, a portion of the reinforcing frame 62 protrudesfrom one end of the supporting frame 36, and as a consequence (as thereinforcing frame 62 and supporting frame 36 have the samecircumferential dimension), a part of the opening in the supportingframe 36 provides a void where the reinforcing frame would otherwise be.

Based on this structure, one half of the rolling element bearing cagemay be connected to another half of the rolling element bearing cage.The protruding portion of the reinforcing frame 62 in one half of therolling element bearing cage may engage with the void in the supportingframe 36 of another half of the rolling element bearing cage. Theportion of the supporting frame 36 having a void may engage with aprotruding portion of the reinforcing frame 62 of another half, byreceiving this protruding portion inserted into the void.

Thus, as shown in FIG. 21B, the two halves of the rolling elementbearing cage may be joined together.

As can be seen in FIG. 21A, the supporting frame 36 is preferablyprovided with internal grooves in first and second annular ringsthereof, which are shaped to accommodate edges (which are also suitablyshaped) of the reinforcing frame. As described above, the supportingframe 36 can be considered as being formed of first and second annualrings, and the reinforcing frame can be considered to be a third annularring. However the reinforcing frame will also be considered to be formedof third and fourth annular rings, which are joined together by its ownretainers which coincide with the retainers of the supporting frame, thereinforcing frame also having spacer portions which coincide with thespacer portions of the supporting frame.

As shown in FIG. 21A, one spacer segment or opening of the reinforcingframe protrudes from the supporting frame, although in general one ormore openings of the reinforcing frame may protrude from the supportingframe. As such, one or more openings of the supporting frame are notaligned with an opening of the reinforcing frame, where the void isprovided in the supporting frame. All other openings of the supportingframe are aligned with an opening of the reinforcing frame.

A rolling element is preferably provided in each opening of theassembled rolling element bearing cage as shown in FIG. 21B. Byinserting a rolling element into each opening, the two halves of therolling element bearing cage are secured, and the two halves cannot bepulled apart.

The rolling element may be any one of a cylindrical roller, a taperedroller, a spherical roller, or a ball. This applies in general to therolling element bearing cage described in any example herein, withreference to FIG. 1 onwards.

It can be seen from FIG. 21A that the reinforcing frame is providedwithin the supporting frame, and the reinforcing frame and thesupporting frame are manufactured to have the same circumferentialdimension. The reinforcing frame is then rotated with respect to thesupporting frame by at least one complete retainer portion, one opening,and part of one further retainer portion. Thereby a section of thereinforcing frame protrudes from the supporting frame and a section ofthe supporting frame has a recess section where the reinforcing frame isrotated from: creating a void. The section of the reinforcing frameprotruding from the supporting frame can engage with the recessedsection of the supporting frame of another segment of the rollingelement bearing cage.

In general, one rolling element is required in order to securely attachone segment of the rolling element bearing cage to another segment ofthe rolling element bearing cage, being a rolling element which ispositioned in a spacer segment which is provided by the supporting frameof one segment and the reinforcing frame of another segment.

In general, as noted above, the reinforcing frame has the samecircumferential dimension as the supporting frame. Each of thereinforcing frame and the supporting frame also has a number of retainerportions which coincide with each other positionally, and the number ofspacer segments which also coincide with each other dimensionally. Whenthe reinforcing frame is fully inserted within the supporting frame suchthat their circumferential dimensions overlap, the retainer portions andthe spacer segments coincide with each other.

In the example of FIGS. 21A and 21B, the insert 62 is provided with aplurality of voids 64 at each of the positions of the resilient tangpairs.

Turning to FIG. 21C, each insert is used to accommodate a “lozenge”.These lozenges may also be made of ToughMet® material. In general thematerial of these lozenges—or inserts in the voids 64—may be the same ordifferent to the materials of the supporting frame or the reinforcingframe.

Thus the final structure, as shown in FIG. 21C, may be formed of threedifferent elements, and each element may be formed of a differentmaterial. Alternatively two or more of the materials may be the same.Alternatively all of the materials may be the same.

Thus with the arrangement of FIGS. 21A to 21C there is provided anarrangement in which two halves of a rolling element bearing cageassembly (which may more generally be extended to two or more segmentsof a rolling element bearing cage assembly) are connected together byvirtue of an insert which is formed with a mechanism for engaging withanother insert in another part of the rolling element bearing cageassembly. This input may be formed of an additional material which isdifferent to the remainder of the cage, or may be formed of the samematerial. Inserts may be added to voids formed therein, such as the“lozenges”, to provide the additional material.

Once thus formed, the rolling element bearing cage assembly formationmay be secured using a rolling element.

The rolling element bearing cage assembly is thus provided havingsections which are joined by parts of the rolling element bearing cageassembly having an inner section and an outer section, with the innersection being angularly rotated relative to the outer section, creatingan engagement mechanism in the inner section which slots into anengagement section of the outer section. Two or more parts (segments) ofa rolling element bearing cage assembly can then be connected.

The inner section preferably protrudes from the outer section by acomplete space segment as shown in FIG. 21A, and a complete retainerportion. A rolling element is inserted in the locations denoted byreference numerals 70 and 72 in FIGS. 21A and 21B, with these rollingelements providing a secure connection for a rolling element bearingcage assembly (which in this case is made up of two halves).

It will follow from an understanding of the above discussion, that thereis also provided a method of forming a rolling element bearing cageassembly, which comprises forming one or more segments such as set outabove. The forming of each segment may thus comprise forming asupporting frame having a plurality of spaced apart openings, forming areinforcing frame including a corresponding plurality of openings eachfor aligning with the openings of the supporting frame, and insertingthe reinforcing frame within the supporting frame. The supporting frameand the reinforcing frame preferably have the same circumferentialdimension.

As shown in the arrangement of FIGS. 21A to 21C, the rolling elementbearing cage assembly may be provided with protrusions on the retainerportions, as denoted by reference numeral 74. These protrusions may rideon an inner race, an outer race, or clamping rings etc.

As well as manufacturing the rolling element bearing cage structure inaccordance with manufacturing techniques for bending and folding amaterial such as a metal material, the rolling element bearing cagestructure may also be manufactured using 3D moulding, 3D printing oradditive manufacturing techniques.

FIG. 22 illustrates half a rolling element bearing cage, an equivalentstructure to that of FIG. 10, formed by 3D moulding, 3D printing oradditive manufacturing techniques.

FIG. 23 illustrates a full rolling element bearing cage structure,equivalent to the view of FIG. 1, formed as a single structure by 3Dmoulding, printing or additive manufacturing techniques.

Examples described herein make reference to the formation of halfrolling element bearing cage assemblies, two of which are connected toform a whole rolling element bearing cage assembly. In practice arolling element bearing cage assembly may be formed of any number ofsegments, and any size of segments of the rolling element bearing cageassembly—such as quarters or thirds—may be made and jointed together.

It should be noted that reference to a cage herein refers to a whole orpart of a cage assembly. Such a cage may be manufactured from any metalmaterial, any plastic material, or any combination of any metal materialand/or any plastic material. A cage may be made from metal or a shapedplastic sheet.

Cages manufactured in accordance with the described examples will notrequire any subsequent bending, folding, riveting or any other machineprocess.

Cages manufactured in accordance with the described examples can bemanufactured with virtually no tool cost.

The invention has been described with reference to particular examplesand embodiments, none of which are limiting. Different embodiments maybe combined, and different features of different embodiments may becombined with features of other embodiments. The scope of protection isdefined by the appended claims.

1. A roller bearing cage comprising: a first annular ring; a secondannular ring; at least one retainer portion attaching the first annularring to the second annular ring to form the first and second annularrings in a cylinder-type structure; and a plurality of resilient tangson each of the first and second annular rings, each tang protruding fromthe circumference of the respective annular ring at an angle withrespect to the plane of the respective annular ring and toward the otherannular ring.
 2. The roller bearing cage of claim 1 in which eachannular ring has an inner circumference and an outer circumference,wherein the at least one retainer portion is connected to the innercircumferences of the annular rings and the plurality of resilient tangsare connected to the outer circumferences.
 3. The roller bearing cage ofclaim 1 wherein each resilient tang has a first tang edge connected tothe respective annular ring and a second tang edge opposite the firsttang edge, wherein the length of the second tang edge is greater thanthe length of the first tang edge.
 4. The roller bearing cage of claim 3wherein ends of the second tang edge define retaining elements.
 5. Theroller bearing cage of claim 3 wherein the edges of the tangs betweenthe first and second tang edges define retaining elements.
 6. The rollerbearing cage of claim 4 wherein the retaining elements are for retainingrollers.
 7. The roller bearing cage of claim 4 wherein the distancebetween the ends of adjacent second tang edges accommodates rollers. 8.The roller bearing cage of claim 3 wherein the third and fourth tangedges joining the first tang edge to the second tang edge are shaped toaccommodate a roller.
 9. The roller bearing cage of claim 8 wherein theshape of the third and fourth tang edges is determined by the angle ofthe tangs to the plane of the annular rings.
 10. The roller bearing cageof claim 1 wherein each annular ring has a circumferential widthdefining a first and second edge, wherein the distance between the firstedges of the annular rings corresponds to the space required toaccommodate a roller at that edge.
 11. The roller bearing cage of claim1 wherein there is provided a plurality of retainer portions, and thespacing between adjacent retainer portions is less than the radius of aroller to be accommodated in the roller bearing cage.
 12. The rollerbearing cage of claim 1 wherein the number of tangs corresponds to anumber of rollers.
 13. The roller bearing cage of claim 2 wherein atleast one retainer portion is joined to the annular rings at acircumferential position on each annular ring which corresponds to thecircumferential position of the first tang ends of an opposing pair ofresilient tangs.
 14. The roller bearing cage of claim 13, wherein thecircumferential position of connection of the at least one retainerportion to the inner circumference of the annular rings is aligned withthe circumferential position of connection of the opposing pair ofresilient tangs to the outer circumference of the annular rings.
 15. Theroller bearing cage of claim 2 wherein there is provided a plurality ofretainer portions attaching the first annular ring to the second annularring.
 16. The roller bearing cage of claim 15 wherein each retainerportion is joined to the annular rings at circumferential positions oneach annular ring which correspond to the circumferential position ofthe tang ends of each of opposing pairs of resilient tangs.
 17. Theroller bearing cage of claim 16 wherein the circumferential position ofconnection of the retainer portions to the inner circumference of theannular rings is aligned with the circumferential position of connectionof the opposing pairs of resilient tangs to the outer circumference ofthe annular rings.
 18. The roller bearing cage of claim 1 wherein theretainer portions are of a thickness such that they form at least partof the tangs.
 19. The roller bearing cage of claim 1 wherein the firstannular ring and the second annular ring each comprise one part.
 20. Theroller bearing cage of claim 1 wherein the first annular ring and thesecond annular ring each comprises two parts.
 21. The roller bearingcage of claim 1 wherein the first annular ring and the second annularring each comprise three or more parts.